Trailer Lights Stay On
 

Hi all. So I have had my 2019 F150 Lariat in twice now because of an issue with my trailer lights. At anytime (night or day) the trailer running lights will stay on continuously. They work fine as far as signals and brake lights but the running lights stay on always no matter what the headlight setting is at. If the truck is in park they will turn off but as soon as you move to drive the trailer lights come on. I have three different trailers which I pull with my truck and have the same issues with all of them. The dealer cannot find any faults with this and is now saying it is part of the trucks programming and something to do with the led headlights in the truck. I am not convinced that is the problem and am wondering if any of you have had the same issue. Thanks

I'll have to connect the TT to the truck tomorrow and check. Never noticed them on but also wasn't looking after doing a bulb check.

Do you have the main light switch in the "auto" position and DRL's on ??

I'd call this a win. I never pull a trailer without clearance lights on. Too many idiots not paying attention out there.

If the TRM signal from the BCM to turn on clearance lamps is pushed off the same circuit that controls power to the front clearance lamps, you'd get exactly this if you set the front clearance lamps to DRL.

Pretty sure my 19 Lariat doesnt do this.

In fact, I have to make sure to turn on the lights to activate power to the camera on my TT.

I can see how it would be a good feature, but not always.

Keep us posted if it is a problem that has a solution(other than selling the truck! LOL)

Yes now I remember same thing, need to turn on the lights to power the backup camera.

My 2020 Platinum does this, but I’ve not yet tried to figure it out. To the best of my recollection, my 2018 Platinum did not.

Mike

With my 2020 XLT the clearance lights on the trailer only come on with night lighting not DRLs.
Or when the wipers are on and the lights activate also briefly when the truck is turned off and I leave the cab.

My 2020 lariat does this. Caught me off guard at first, but it is normal

Yes, that is normal, but you can go into FORScan and make a change so that your front yellow lamps serve as DRL's. If the trigger for the trailer clearance lights is derived from the BCM output for the front yellow lamps, you'd have trailer clearance on when DRL is on.